No head gear, no head kicks and you HAVE to take it easy on the head hunting. On both sides, no excuses, or you go home.

Mouth guard... ehhh not really that much of a big deal. I know it should be but if you want one, then you buy one. That's all, you're the one who's gonna have fucked up teeth at the end of the day and you've been told to bring it with you.

Aside from that I like head gear. Less cuts, makes shots to the forehead a little less painful and prevents cauliflower ear.

My gym mandates that we wear headgear while sparring. It doesn't bother me too much aside from not being able to see people's faces as well as I would like but that doesn't matter because I'm not supposed to be looking there anyway. :P

Some sparring partners encouraged me to get headgear because that way, partners wouldn't hesitate to kick the head. I find that since beginning wearing the piece regularly, my partners would go for the head. Consequently, I have gotten better at keeping my hands up. ;)

Tragically and somewhat ironically, the Army doesn't support us performing full contact outside of Army Combatives courses. So headgear, with some kind of face shielding, is essential to me keeping my rank.

And Maofas I went with a Combat Sports Face cage reccomended by MingLoyalist. It is expensive, but is keeps you from showing up to work looking like you got worked over. I will freely admit haven't had a chance to put it to a real test however.

I don't really consider that expensive (not that I make a lot of money). When I was bitching about expensive I was thinking ~$200 with shipping from Japan/Canada for Daido Juku or Top 10 Boxing headgear.

That face cage joint looks heavy though, and I'm not sure if the bars are a significant hindrance to your visibility, but I bet the cheek pads are (judging from my past experience with boxing training headgear that's similarly shaped minus the cage). They make it really hard to see kicks coming until way late in the kick, unless you hold your head down at an unnatural angle. I used to just wear open face headgear and rub a little Vaseline on my nose if I was doing hard contact, but I'm going to feel like a jackass if I wind up breaking my nose again after spending all that money. I figure, if I have to wear some ridiculous contraption and look like a retard, at least I should get perfect visibility.

Edit: I saw a picture of that headgear today without the face cage, actually those cheek pads go up a lot less high than I thought, hmmmm!!!

I always spar with headgear and a mouth piece; it is required at our dojo.

Personally, I could live without it. There are very few people who venture to kick me in the head, and otherwise any other shot that actually lands in that area will still hurt with or without cumbersome sweaty head gear. All in all, I really don't care either way. If they want me to wear it, I won't complain.

At my old dojo, headgear and shin pads were a must if you weren't a black belt. If you "forgot" it, there were extras in the ol' equipment bin. Everybody had to wear a mouthpiece and if you forgot it, you had to pay for one on the spot or go home.

I don't have my students put on headgear unless they are going heavy/full contact with MMA gloves in. If it's lighter contact than that, or if they have boxing gloves, I don't see much of a need for it.

From a safety perspective, it's repetitive abuse that causes brain trauma, so more impact can be safer in many ways (the old MMA vs Boxing argument). Beyond that, like others have mentioned, the headgear prevents cuts, and bad bruising so you can show up at work the next day.